Thermal Evaluation of Some Locally Sourced Activated Carbons from Agricultural Residues

Abstract

Activated carbons are progressively used as an economical and stable mass separation agent for eliminating surfactants to raise the final product property in many industrial processes. Activated carbon has various applications in different fields, and it performs differently at different temperatures; hence this paper presents a thermal experimental characterization of some locally produced activated carbon from agricultural residues. The experiment was done on the locally produced activated carbon from coconut shell, coconut husk, palm kernel shell, maize husk and imported activated carbons. The adsorbate used is Methylene Blue (MB), the samples were agitated in a water bath shaker at different concentration of adsorbate (50, 100, 150 and 200 ppm) and different temperatures (30 ^oC, 40 ^oC, and 50 ^oC). Adsorption isotherm study is carried out on two well-known isotherms; Langmuir and Freundlich isotherm models. The results revealed that the adsorption capacity of the five samples increased with temperature and initial dye concentration. The adsorption in the samples follows the Langmuir Isotherm model that implies homogenous adsorption and Maize husk has the highest monolayer adsorption capacity at 40 ^oC. Hence the carbons will perform satisfactorily under heat as the combination of adsorbent and adsorbate in adsorption refrigeration system. The locally produced activated carbons compared favourably with imported activated carbon, hence locally produced activated carbons can replace imported activated, to reduce dependency on foreign product and improve the economy of the country.

Keywords: Evaluation, Activated carbon,Adsorption Isotherm, Agricultural Residues